The invention relates to systems (i.e., compositions) which harden rapidly in the absence of oxygen, based on (meth) acrylic esters and organic peroxides, particularly hyperoxides, which are known as anaerobic adhesives, sealing compounds, and the like, and which contain an agent which improves their storage-stability. They are preferably used in solvent-free form for the above mentioned purposes. The invention includes methods for the preparation of these composition.
As essential components these systems contain monomeric or oligomeric (meth) acrylic esters of mono- or polyvalent alcohols, as well as a peroxide or hydroperoxide. In order to ensure sufficiently rapid hardening in the absence of oxygen, accelerators are added to the systems. For the purpose it is known that, for example, amines, particularly tertiary amines, carboxylic hydrazides, N,N'-dialkyl hydrazines, and carboxylic sulfimides are effective. Many of these accelerators have, however, caused the adhesives to polymerize prematurely in storage and thus to become usable.
Accordingly, a demand has arisen for compositions of the type mentioned which contain an agent which renders the compositions adequately storage-stable but which does not interfere with the beneficial properties of the composition.